Measuring and dispensing devices are well known in the art. However, most such measuring and dispensing devices are not suitable for use with a bulk material having a high density such as toner used in a laser printer cartridge or copier machines. The prior art devices which are used to fill cartridges with toner also have many disadvantages and are not suitable for efficiently recycling laser printer cartridges.
Measuring and dispensing devices such as those disclosed in U.S. Pat. Nos. 1,291,759; 480,146; and 817,727, are for use with materials such as coffee, snuff and other such loosely packed powdered materials. Such devices are not suitable for measuring and dispensing a bulk material such as toner because of the characteristics of such a material having both fine particles and a high density. A material having such a high density will not flow easily from the hopper to the measuring chambers in the prior art devices without displacement of the air in the measuring chamber.
Furthermore, measuring and dispensing a bulk material such as toner can be messy and requires a measuring and dispensing system which is sufficiently closed to contain the bulk material and prevent the bulk material from spilling out of the system or contaminating parts of the system. The dispensed materials such as coffee and snuff which are dispensed with the prior art measuring and dispensing devices mentioned above do not cause the same concerns as high density and contaminating materials such as toner. Therefore, the prior art devices are not designed to allow the material to easily flow while preventing contamination by the material into the measuring and dispensing system itself as well as into the outside area around the system.
In the prior art, there are known systems and methods for recycling laser printer cartridges by dispensing toner into the cartridge. However, problems are often encountered with such methods and systems for replacing the toner in a cartridge. Recycling toner by using small bottles containing the exact amount of toner for the cartridge is wasteful and inefficient. The bulk loading machines available in the prior art also present problems. Such bulk loading machines are often big and expensive. Also, bulk loading machines in the prior art often do not allow the bulk material such as toner to be precisely volumetrically measured prior to dispensing. Further, different cartridges often take different types of toner and the big bulk material loading machines available in the prior art would be difficult to adapt to measure and dispense different types and volumes of toner into the various cartridges.
One prior art system for dispensing toner uses an auger mechanism to cause the toner to flow from a hopper to a toner cartridge and provides a vent from a spout to the hopper. This system is more costly and complex than a simple and efficient measuring and dispensing system which primarily uses gravity to cause the toner to flow. Further, the vent used on the prior art device would not maximize the flow of toner in a measuring and dispensing device which does not use an auger mechanism to cause toner to flow.
Accordingly, what is needed is a bulk material measuring and dispensing system which involves a simple, cost efficient mechanism and can measure and dispense a predetermined volume of bulk material having a high density, such as toner. Such a device must provide proper venting for the high density bulk material to easily flow from a container to the volumetric measuring device and then to the cartridge or receiver, while preventing the bulk material from contaminating the device and the surrounding area. Further, such a device should be adaptable for different types of toner.